Frameless glazed formations with plane surface

ABSTRACT

A frameless flat glazed comprising a rear wall of chip board, for example having one or more glass support brackets at the bottom thereof and one or more hanger eyelets mounted on the back. A picture or other article to be protected is sandwiched between the rear wall and a glass sheet. The edges of the composite are attached and sealed solely by a room-temperature curing organosiloxane-based elastomeric material which is coated on the edges of the composite.

United States Patent Inventors Rudolf Schneider; [56} References Cited Richard Kastner, both of Munich, UNITED STATES PATENTS Gem? 2,330,292 9/1943 Kni 111 et a]. 40/152 P 236,845 l/l88l Schiurich 40/152.1 F'led 2 2,268,529 12/1941 Stiles 40/152 f 3 G b H 2,281,054 4/1942 Smith et al..... 40/156 Ass'gnee 2,527,765 10/1950 Roehrl 40/159 Munich, Germany priority 6, 19 6 FOREIGN PATENTS Germany 1,096,066 12/ l960 Germany 40/152 w42923 472,446 2/1929 Germany 40/152 Primary Examiner-Robert W. Michell Assistant Examiner-Wenceslao J. Contreras AttomeysRobert F. Fleming, Jr. and Laurence R. Hobey FRAMELESS GLAZED FORMAT'ONS WITH ABSTRACT: A frameless flat glazed compnsmg a rear wall of chip board, for example having one or more glass support E F brackets at the bottom thereof and one or more hanger eyelets 8 mounted on the back. A icture or other article to be ro- P P US. Cl 40/152 tected is sandwiched between the rear wall and a glass sheet. G09f 1/12 The edges of the composite are attached and sealed solely by a Field at Search 40/152, room-temperature curing organosiloxane-based elastomeric 154, 152.1, 156, 10 material which is coated on the edges of the composite.

FRAMELESS GLAZED FORMATIONS WITH PLANE SURFACE BACKGROUND OF THE INVENTION The present invention relates to glazed structures and more particularly to frameless glazed structures for protecting pictures or the like.

Frameless flat glazed structures consisting of a rear wall provided with at least one hanger eyelet and at least one support for the glass pane, i.e., the hanger apparatus, the article to be protected by the glass pane, and a glass pane are known. The known arrangements of this kind, in which the structures to be protected by the glass pane are pictures, for example valuable drawings or graphics or printed items have the disadvantage that dust can penetrate under the glass pane and settle on the articles which are to be protected. Valuable pictures and printed items could therefore not be stored for an extended period of time, normally not more than a few months, in frameless glazed form in rooms which were not made dustfree. Furthermore, the clamps which were necessary to hold such items together were found to be aesthetically disturbing. Such clamps and/or the expense associated with adhesion to the rear wall because of the large surfaces which need to be covered were also found to be a disadvantage when a frameless flat article to be glazed involved a mirror coating, i.e., the reflecting component of a glass mirror.

SUMMARY OF INVENTION It is an object of the present invention to provide frameless, flat glazed articles in which no dust can penetrate.

A further object is the provision of frameless, flat glazed mirrors in which the mirrored surface need not be adhered to the rear wall.

Another object is to provide frameless, flat glazed articles in which holding clamps which affect vision and appearance are unnecessary.

In accordance with these and other objects, there are provided by the present invention frameless, flat glazed articles consisting of a rear wall provided with at least one hanger eyelet and at least one support for the glass pane, the article to be protected by the glass pane and a glass pane characterized in that the edges, at least of the rear wall and of the glass pane, are attached to each other by a coating prepared from organosiloxane based materials which may be stored when water is excluded and which will harden to elastomers at room temperature when water is admitted.

BRIEF DESCRIPTION OF THE DRAWING The invention will become better understood and other objects and advantages will become obvious to those skilled in the art by a consideration of the following detailed description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic cross section of a flat frameless glazed structure made in accordance with the invention, and

FIG. 2 is a rear view in elevation of the embodiment shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings wherein like reference characters designate like parts in both of the figures thereof, there is shown in FIG. I a schematic cross section and in FIG. 2 a view of the back of a frameless glazed article according to the present invention. In FIG. 1 the fact must be taken into consideration that in actuality no, or practically no, spaces exist between the backwall 1 and the article 2 to be protected by the glass pane as well as between this article and the glass pane 3. In FIG. 2 the fact must be taken into consideration that the relationship of the thickness of the coating 6 to the plane of the rear wall 1 is normally much smaller than could be represented here.

Simple flat plates, for example of plastics, metals, wood, wood products such as chip board or asbestos are suitable as the rear wall I for the frameless glazed articles of the present discovery. Chip boards are preferred because they are espe cially easy to obtain. If desired, the edges of these plates which are away from the glass pane may be beveled or rounded off. At least one ordinary hanger eyelet 5 is fastened in the ordinary manner to the plates. For aesthetic reasons, the hanger eyelets can be applied in such a manner that they do not extend beyond the rear wall and the glass plate.

This kind of attachment for the eyelets is shown in FIG. I and FIG. 2. For aesthetic reasons and because they are readily obtainable, angle plates of plastic or metal, especially metal, screwed to the lower portions of the rear wall and extending at most up to the foreside of the glass plate as shown in FIG. 1 are preferred and, surprisingly, are completely satisfactory and serve as the supports 4 which must carry most of the weight of the glass plate.

The articles 2 which are to be protected by the glass plate may be any desired flat articles of the same type which have or could hitherto have been placed under frameless glass. Examples of such articles are drawings of all kinds, aquarelles, graphics and printed material such as pages from valuable incunabula, as well as films applied directly to the glass plate such as paintings done on the underside of the glass and mirror films. Passe-partout may be included, if desired.

The glass panes 3 are preferably ground glass panes which are commonlyused for the preparation of frameless glazed pictures.

Any known organopolysiloxane-based materials which can be stored under conditions which exclude water and which will cure to high strength elastomers at room temperature when water is admitted may be used for preparing the coatings 6 of the present invention. Such materials are prepared by mixing diorganopolysiloxanes displaying one reactive group in each terminal unit, that is one Si-bonded hydroxyl or amino group, especially dimethylpolysiloxanes, with compounds displaying at least three reactive groups per molecule. Examples of such compounds with at least three reactive groups are compounds of the general formula RSi(ORl) wherein R is a hydrocarbon radical, usually the methyl radical, and R is an acyl radical, usually the acetyl radical or a group of the formula R,C=N, wherein each R is as above defined; compounds of the general formula RSi(NR" wherein R is as above defined and each R"is H, a hydrocarbon radical, preferably the cyclohexyl radical or an acyl radical; as well as aluminum alcoholates. I

Organopolysiloxane-based materials which may be stored under exclusion of water and which will cure to elastomers at room temperature upon addition of water are described, for instance, in British Patents 905,364, 944,061, 975,603 and 1,041,055 as well as U.S. Pat. applications Ser. No. 615,350, filed Feb. 13, 1967, Ser. No. 6l5,320,filed Feb. 13, 1967, Ser. No. 617,063, filed Feb. 20, 1967, and Ser. No. 669,675, filed Sept. 22, l967.

Coating 6 is preferably prepared from those organopolysiloxane-based materials which may be stored under exclusion of water and which will cure to elastomers at room temperature when water is admitted, for whose preparation SiN-bonded aminonitrogen atom-containing compounds were used to serve as the aforementioned compounds with at least three reactive groups.

A particularly preferred and commercially obtainable material of this kind is prepared according to the following description.

0.5 ml. dimethylbis-(cyclohexylamino)-silane is mixed with a mixture of 40 g. of a dimethylpolysiloxane containing one hydroxyl group in each terminal unit, said siloxane having a viscosity of 80,000 cs. at 25 C., 10 g. of a trimethylsiloxy endblocked dimethylpolysiloxane having a viscosity of 50 cs. at 25 C., 50 g. quartz flour and 2 g. silicon dioxide prepared pyrogenically from the gas phase. After 45 minutes the mixture thus obtained is mixed with 3 ml. methyltris-(cyclohexylamino)-silane. The material is then ready to be applied to obtain the coating 6.

If no wood or chip board plate is used as the rear wall or if some other polysiloxane-based material, which is storage-stable under exclusion of water and which may be cured to elastomers at room temperature when water is admitted than that described above is used, then the surfaces which are to be coated with this material may have to be primed before producing the coating of the present invention. Primers which are commonly used with organopolysiloxane elastomers, for instance mixtures of methyltriethoxysilane, tetrabutyltitanate and acetylacetone, may be used for this.

The materials hardening to elastomers are applied to all edges, i.e., narrow sides of this assembly, for example from a tube, in order to create coating 6 after the rear wall 1, with its supports 4 and eyelets 5, the article 2 to be protected by the pane of glass and the glass pane 3 have been combined as shown in FIG. 1. As can be seen from FIG. 2, the supports 4 may cross the coating.

Coatings from 2 mm. down to 0.3 mm. thick are entirely sufficient to hold the assembly together without the clamps, which in prior art configurations covered the glass plate at least slightly, being necessary. This is extraordinarily surprising when one considers that none of the usual surface-to-surface agglutinations are used. Film depths of 0.3 mm. to 1 mm. are preferred. Hardening of the materials to an elastic coating requires about minutes to one day and occurs spontaneously, i.e. without mixing other additives into the mass. The material may be smoothed immediately after the application with a knife, for instance.

While the invention has been described with reference to specific embodiments, various modifications thereof will be readily apparent to those skilled in the art. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

That which we claim is:

1. ln frameless, glazed plane-surfaced articles consisting of a rear wall with at lest one hanger eyelet and at least one support, a glass pane, and the article to be protected by the glass pane, the improvement which comprises the edges at least of the rear wall and the glass pane being held together with a coating prepared from organopolysiloxane-based materials which can be stored under exclusion of water and which will harden to elastomers when water is admitted, said materials being prepared by mixing diorganopolysiloxanes displaying one reactive group in each terminal unit with compounds displaying at least three reactive groups per molecule.

2. Frameless, glazed articles as defined in claim 1 wherein the coating is prepared from organopolysiloxane-based materials in which during preparation SiN-bonded aminonitrogen atom-containing compounds were used as the said compounds with at least three reactive groups.

3. Frameless, glazed articles according to claim 2 characterized in that the supports for the glass pane are metal angle plates screwed to the lower portion of the rear wall 1 and extend at most to the foreside of the glass pane. 

1. In frameless, glazed plane-surfaced articles consisting of a rear wall with at lest one hanger eyelet and at least one support, a glass pane, and the article to be protected by the glass pane, the improvement which comprises the edges at least of the rear wall and the glass pane being held together with a coating prepared from organopolysiloxane-based materials which can be stored under exclusion of water and which will harden to elastomers when water is admitted, said materials being prepared by mixing diorganopolysiloxanes displaying one reactive group in each terminal unit with compounds displaying at least three reactive groups per molecule.
 2. Frameless, glazed articles as defined in claim 1 wherein the coating is prepared from organopolysiloxane-based materials in which during preparaTion SiN-bonded aminonitrogen atom-containing compounds were used as the said compounds with at least three reactive groups.
 3. Frameless, glazed articles according to claim 2 characterized in that the supports for the glass pane are metal angle plates screwed to the lower portion of the rear wall 1 and extend at most to the foreside of the glass pane. 